Low End Mac's Sebastian Patten takes a look at MorphOS 3. "MorphOS is for Amiga users. Period. And it's for those Macintosh users who like to experiment and experience a new operating system on their PowerPC Macs. That's where I see myself, and I had a lot of fun playing around with MorphOS on my eMac. It is not a full OS X replacement, but it can come close to it, depending on your computer needs."

Not my experience. I've used Linux on an iBook G3 12" from 2003 till 2005. From then on I've been using Linux on an iBook G4 12" (my G3 was replaced by Apple because of motherboard problem). Actually, the last couple of months I've been using it daily on the train ride to and from work.

In the first couple of years, I ran Gentoo Linux, and for the rest up to this day, it's been running Debian Linux (testing). Back in 2003, the iBook G3 hardware was fully supported with open source drivers except for the software modem in it. But for example sleep was working perfectly. In 2005, the iBook G4 hardware was not fully supported yet: there was still a lot of work on the driver for the wifi card. Nowadays the hardware is fully supported.

Regarding software, there are only 2 important issues. And those were the same in 2003 as they are now in 2012. These are support for flash and java. For flash, there is no linux/ppc binary from Adobe, and the only option is open source projects like gnash. In practical terms, that means no flash on linux/ppc. As to java, actually IBM has a binary JDK that runs on linux/powerpc. Aside from that, also OpenJDK runs on linux/powerpc. OpenJDK in Debian has also extra packages to use OpenJDK with the cacaovm and jamvm (aside from the interpreter that comes with OpenJDK). Cacao contains a jit compiler for linux/powerpc.

Linux on powerpc definitely does not look like an afterthought to me. It is however important to choose a distro that actually supports the platform. I guess that since Apple moved their hardware over to the x86 platform, there's less interest in linux/powerpc and of course also few(er) hardware available for linux/powerpc. Unless maybe someone builds something like a raspberry pi, but based on a powerpc cpu?